1. Field of the Technology
This invention relates generally to electrical connection structures for magnetic recording devices, and more particularly to an electrical connection structure having an electrically conducting diffusion barrier layer which reduces or eliminates oxidation of a top surface of an electrically conductive etch stop layer of the electrical connection structure.
2. Description of the Related Art
Computers often include auxiliary memory storage devices having media on which data can be written and from which data can be read for later use. A direct access storage device (disk drive) incorporating rotating magnetic disks are commonly used for storing data in magnetic form on the disk surfaces. Data is written on concentric, radially spaced tracks on the disk surfaces by a write head, and is then read by a read head. Thin film magnetic heads are primarily used in magnetic storage systems to write/read information in the form of magnetic pulses to/from the disk. A magnetic transducer, such as an inductive or magnetoresistive head (e.g. MR or GMR type), includes a read sensor which detects a magnetic field through the change in the resistance of its sense layer as a function of the strength and direction of the magnetic flux being sensed by the sense layer. The magnetic head is typically formed on a slider which is then mounted to a suspension arm of an actuator. The suspension arm suspends the head in close proximity to a disk surface.
Electrical current flows through the read sensor through low electrical resistance paths known in the art as lead layer structures. These lead layer structures are terminated at the trailing edge of the slider and are connected to an electrical current source through electrical connections known in the art as “vias”. When the electrical connections include a metal that is prone to oxidation, the surface oxide can impede the flow of the electrical current through any via utilized for the electrical connection.
One example is an electrical connection structure which includes copper (Cu) and tantalum (Ta), where the Ta is utilized as an etch stop layer. In this example, a lead/shield layer of nickel-iron (NiFe) needs to make electrical contact with the lead layer structure through the via. During the fabrication process, the top surface of the Ta is exposed to oxygen whereby the surface of the Ta oxidizes, thereby becoming electrically resistant. If the lead/shield layer is subsequently deposited in contact with this oxidized surface then a parasitic resistance results.
One known solution utilizes in-situ sputter cleaning or in-situ ion milling prior to the deposition of the lead/shield layer. Disadvantages of this approach include an increased likelihood of damage to other structures in the magnetic head. Specifically, in the above example, a read gap layer is damaged and/or thinned by the sputter cleaning or ion-milling. This damage reduces the desired characteristics of mechanical stability, chemical stability, and low contact resistivity.
Accordingly, what are needed are improved electrical connection structures for magnetic recording devices and methods of making the same.